1. Field of the Invention
The present invention relates to a positioning apparatus and a positioning method.
2. Description of the Related Art
A positioning apparatus for detecting (positioning) a position of itself (for example, [Latitude, Longitude], or a position on a map) is known. For example, Japanese Laid Open Patent Application (JP-P 2004-239803A) discloses a technique of a position detecting terminal and a position detecting system. This position detecting terminal has a map storing unit for storing map information, a map area specifying unit for inputting a displaying range of the map information, a position detector for obtaining position information of the terminal itself, and a display that can display the position information and the map information. This terminal has a positioning starter for activating the position detector when the displaying range of the map information is specified narrower than the displaying range indicated by a preset positioning operation start level. FIG. 8 is a block diagram showing this position detecting terminal T.
This position detecting terminal executes the positioning by the procedure as described bellow. At first, the user uses an input unit and inputs a schematic position and a displaying range of a map to a map area specifying unit 102. The specification of the schematic position is exemplified by the specification of a nearby station name or the like. The map area specifying unit 102 refers to a map storing unit 101 and displays the map and the schematic position on a display 104. When the user requests the narrower range or requests the detailer map in the first range specification, a positioning starter 105 uses a position detector 103 and carries out the positioning. When there are a plurality of position detectors 103, a positioning method (any of a GPS positioning unit 103a and a wireless base station usage positioning unit 103b) corresponding to a specified positioning precision is selected to carry out the positioning. The detailer map is obtained correspondingly to the positioning result.
In the example of Japanese Laid Open Patent Application (JP-P 2004-239803A), the positioning method is changed correspondingly to the specified displaying range. For example, if the specified displaying range is the displaying range stored in advance in the map storing unit 101 such as a wide area map, the positioning is not especially executed. When the displaying range becomes detailer, the positioning is executed. As the displaying range becomes detailer, the accuracy of the positioning is enhanced. As a result, the more accurate position information corresponds to the detailer map.
However, after the positioning of the low precision is executed to obtain the position information, when there is the input of the user requesting the detailer position information, the repositioning of the high precision is required. In this case, in addition to the time necessary for the positioning of the low precision, the time necessary for the input operation of the user and the time necessary for the positioning of the high precision are required successively and excessively. Thus, the satisfaction of the user is decreased.